Quiet some jshint complaints on asm-llvm.
asm-llvm: propagate direct +(expr) coercion to call site.

Also removed the old 'noIn' propagation (used to parse for-in loops)
and the 'noCalls' parameter (used to parse 'new ...' expressions).
asm-llvm: Broaden the function return types to intish/doublish.

Corresponding asm.js spec change discussed in
https://bugzilla.mozilla.org/show_bug.cgi?id=854061#c3

Make `void` a subtype of `intish`, as described in
https://bugzilla.mozilla.org/show_bug.cgi?id=854061#c4